Conventionally, a known EGR device may be employed to recirculate a part of exhaust gas as EGR gas into an intake air passage thereby to reduce nitrogen oxide (NOx) contained in exhaust gas emitted from an engine. For example, Patent Document 1 discloses an EGR device equipped with an EGR cooler to cool EGR gas, which is recirculated into the intake air passage. The EGR cooler is supported with a singular mounting stay, which is connected to an engine main body and is further connected to a part of an intake pipe.
(Patent Document 1)
Publication of unexamined Japanese patent application No. 2000-248936
According to the conventional configuration disclosed in Patent Document 1, the EGR cooler is supported as a singular component via the mounting stay. In addition, the EGR cooler is connected with other components, such as the EGR valve unit, via a flanged pipe. Therefore, the conventional configuration may not restrict relative movement between the EGR cooler and the other components due to oscillation. Consequently, stress may be applied to the flanged pipe to cause cracking and/or breakage in the flanged pipe. Furthermore, the conventional configuration may not absorb displacement caused by difference in thermal expansion between the EGR cooler and the other components. Consequently, the conventional configuration may cause leakage of EGR gas.
Furthermore, according to the conventional configuration, the EGR cooler and the other components are connected with each other via the flanged pipe. Therefore, connection between the EGR cooler and the flanged pipe takes a long time. In addition, the conventional configuration requires bolts screwed to connect flanged pipe. Consequently, the conventional configuration may require high manufacturing cost.